Consulting

New Global Scratch File System

September 11, 2013
by Francesca Verdier
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NERSC is pleased to announce the availability of a new file system: /global/scratch2. This file system is intended to replace the current /global/scratch, and is mounted on all NERSC platforms that mount /global/scratch. A new environment variable GSCRATCH2 has been created that points to your personal scratch directory in /global/scratch2.

/global/scratch2 has 3.6 PB of space and an aggregate peak bandwidth of 80 GB/second.

NERSC will not move data from /global/scratch to /global/scratch2. Because much data in /global/scratch is (by definition) temporary, users will be expected to decide what to move to /global/scratch2, what to move to HPSS, and what to discard.

Please begin migrating to the new file system. In particular, if you have batch jobs on Carver that use GSCRATCH, please modify your batch scripts so that they refer to GSCRATCH2 instead of GSCRATCH. Note that you may have to copy input data to your new /global/scratch2 directory.

On October 8 we will make /global/scratch read-only. Tthe GSCRATCH environment variable will then refer to /global/scratch2; there will be *no* environment variable referring to /global/scratch at that point. Also, any attempts to write to /global/scratch will fail. About three weeks after this date, /global/scratch will be retired, and all data left on the filesystem will be discarded.